Data collected for the mapping cooperative have been released in a series of USGS Open-File Reports<http://woodshole.er.usgs.gov/project-pages/coastal_mass/html/current_map.html>. This spatial dataset is from the Cape Ann and Salisbury Beach Massachusetts project area. They were collected in two separate surveys in 2004 and 2005 and cover approximately 325 square kilometers of the inner continental shelf. High resolution bathymetry and backscatter intensity were collected in 2004 and 2005. Seismic profile data, sediment samples and bottom photography were also collected in 2005.
U.S. Geological Survey, 2008, BATH_OS5m - 5 meter ArcRaster grid of multibeam bathymetry of the offshore area of Cape Ann - Salisbury Beach Massachusetts Survey Area.: Open-File Report 2007-1373, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, Massachusetts.This is part of the following larger work.Online Links:
Barnhardt, Walter A. , Andrews, Brian D. , Ackerman, Seth D. , Baldwin, Wayne E. , and Hein, Christopher J. , 2008, High-Resolution Geological Mapping of the Inner Continental Shelf: Cape Ann to Salisbury Beach, Massachusetts.: Open-File Report 2007-1373, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, Massachusetts.Online Links:
This is a Raster data set. It contains the following raster data types:
Planar coordinates are encoded using row and column
Abscissae (x-coordinates) are specified to the nearest 5.001120
Ordinates (y-coordinates) are specified to the nearest 5.001120
Planar coordinates are specified in meters
The horizontal datum used is D_WGS_1984.
The ellipsoid used is WGS_1984.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257224.
Range of values | |
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Minimum: | -7.88 |
Maximum: | -91.41 |
Units: | meters |
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The purpose of these data is to establish high-resolution acoustic depth measurements of the seafloor for regional geologic framework investigations. These data cover 257 square kilometers of the offshore survey area between Cape Ann and Salisbury Beach, Massachusetts, in depths between 7 m and 91m. The data were collected by Science Applications International Corporation (SAIC), in 2004 for the USGS, under contract to the University of New Hampshire.
A patch test was conducted at the beginning of the survey in order to measure roll angle offsets. Roll angle offsets can have a strong effect on the accuracy of depth measurements. The roll angle offset is the difference between the motion sensor vertical measurement and the nominal mount angle of the transducers. The calculated roll angle offsets were stored within the SABER acquisition software.
Once the data were in Newport and had been extracted to local machines, track lines were created by extracting the sounder position from the multibeam data. The tracks were reviewed to confirm that no errors in navigation existed and that the tracks extended to the outermost bounds of the survey area.
After the application of preliminary tides and interpolated draft, multibeam binned-depth grids were generated. A 5-meter Pure File Magic (PFM) grid was generated and edited in area based mode using MVE. The 5-meter projected PFM allowed multiple line editing which enhances visualization and proves efficient in the MVE process to ensure data quality. If any anomalies were found in the sounding bins, the edited multibeam files were re-examined and re-edited as necessary. When all multibeam files were determined to be satisfactory, the data were binned to a 5-meter and 2-meter cell size, populating the bin with the average of all soundings in the bin and maintaining the position of the center of the bin.
Person who carried out this activity:
401-847-4210 (voice)
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Person who carried out this activity:
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bbutman@usgs.gov
A new CARIS HIPS project (ver 6.1) was created with the projection information set to Universal Transverse Mercator (UTM) Zone 19, WGS84. The Processed GSF files for all main scheme lines were imported to CARIS using the import/conversion wizard A 5 meter Bathymetry and Statistical Error (BASE) surface was built from the line files. All previous edit flags were imported and no further editing was done in CARIS.
Person who carried out this activity:
508-548-8700 x2348 (voice)
508-457-2310 (FAX)
bandrews@usgs.gov
Person who carried out this activity:
508-548-8700 x2348 (voice)
508-457-2310 (FAX)
bandrews@usgs.gov
Barnhardt, Walter A. , Andrews, Brian D. , and Butman, Bradford, 2006, High-Resolution Mapping of the Inner Continental Shelf: Nahant to Gloucester, Massachusetts: Open-File Report 2005-1293, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.Online Links:
Ackerman, Seth D. , Butman, Bradford, Barnhardt, Walter A. , Danforth, William W. , and Crocker, James M. , 2006, High-Resolution Geologic Mapping of the Inner Continental Shelf: Boston Harbor and Approaches, Massachusetts: Open-File Report 2006-1008, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.Online Links:
Science Applications International Corporation (SAIC), 20040430, Southern Merrimack Embayment Multibeam Survey, Survey Report: Survey Report, SAIC, Newport, Rhode Island.Online Links:
These data were navigated using data from U.S. Coast Guard Differential Global Positioning System (DGPS) network.
Vertical accuracy of <= to 0.5 meters for 95.8 percent of the soundings in water depths between 7-91 meters. These data were quantitatively compared by cross line junction analysis. 95.8 percent of the comparisons were within 50 cm (vertical) of each other. Ship motion (heave, pitch, yaw, roll) was recorded with a TSS POS/MV 320 Position and Orientation System. The NOAA tide station in Portland, ME 8418150 was the source of preliminary water level heights for Cape Ann to Salisbury Beach offshore survey area. Preliminary tide data for this station were downloaded from the NOAA CO-OPS web page <http://www.co-ops.nos.noaa.gov/> hydro.html). All tide data were annotated with Coordinated Universal Time (UTC).
The zoning parameters SAIC created were: On Portland, ME (8418150) + 8 minutes ratio 0.964 On Boston Light, MA (8444162) +2 minutes ratio 0.972 All bathymetry data collected during the survey were corrected for water level variations using water level files. Water level files for each tide zone were created from downloaded preliminary NOAA tide data using the Survey Analysis and area Based Editor (SABER) Create Water Level Files tool. Water level files contain water level heights that are subtracted algebraically from depths to correct the sounding for tide and water level. These water level files were applied to the multibeam data using the Apply Tides tool within the SABER software.
Comparison of the zoned 6-minute water level heights computed from Boston Light, MA (8444162) to those computed from Portland, ME (8418150) shows an average height difference of 0.009 meters and a standard deviation of 0.042 meters. The maximum and minimum differences were +0.125 meters and -0.078 meters. Because the Portland, ME (8418150) gauge is a NOAA Primary Control Tide Station water level zoned heights from that station were used to correct the soundings.
Sound velocity casts were taken every 2-4 hours with a Brooke Ocean Technology MVP 30 System and Applied Microsystems Smart Sound Velocity Sensor.
Survey lines run for cross line junction analysis are not included in this grid.
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints:
- The intended scale of these data is 1:25,000 Data are not intended for navigational use. Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS) as the source of this information.
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bandrews@usgs.gov
Downloadable Data
Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Data format: | Grid containing high-resolution bathymetric data collected in the offshore survey area of the Cape Ann to Salisbury Beach Survey Area. in format ESRI Grid (version ArcGIS 9.2) ESRI Raster GRID format Size: 89.887 mb |
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Network links: |
<https://pubs.usgs.gov/of/2007/1373/GIS/raster/bathymetry/bath_os5m.zip> |
Media you can order: |
DVD-ROM
(Density 4.75
Gbytes)
(format UDF)
Note: None
|
These data are available as a ArcInfo 32-bit floating point binary grid in Environmental Systems Research Institute (ESRI) format. The grid consists of two folders, one with the "grid name", and one "info" folder. The two folders for each grid are compressed into one file using WinZip (ver. 9.0) software. To utilize these data, the user must have software capable of uncompressing the WinZip file and importing and viewing an ESRI ArcRaster grid. The two folders for each grid must be uncompressed to the same folder. If during the process of extracting multiple grids in WinZip format to the same folder, the user is prompted by WinZip software to "overwrite existing files" in the info folder select the "yes" option.
508-548-8700 x2348 (voice)
508-457-2310 (FAX)
bandrews@usgs.gov